"The Joys and Sorrows of 3D Printing"
For our seventh meeting, EAST Knowledge was delighted to host Michael Yurkoski on the topic of 3D printing. Michael presented a little bit of the history of additive manufacturing, quickly dived into the practical details of hobbyist 3D printing, and finished off his presentation with a live 3D printing demo. The presentation was a terrific, densely packed performance, and I think even people who had been doing 3D printing for a while learned something new. With the usual apologies for not being able to do the speaker justice with our meager notes, we will do our best to provide an overview of what was presented. Michael's slides are here and also available at the bottom of the post, and we recommend you check them out for more information.
Besides Michael, other people brought their 3D printers to show as examples of the different options available. This was a great supplement to the main talk as it gave us in the audience a good appreciation for the variety of printers available even when they all use the same technology.
Additive vs Subtractive Manufacturing
Michael started off the talk by contrasting subtractive manufacturing with additive manufacturing. Subtractive manufacturing is where you start with more material than you need and then remove material until you've made what you want. Examples are CNC mills, routers, cutters, etc. Most of what people think about when they think of modern industrial manufacturing is subtractive.
Additive manufacturing is where you start with the raw material and build up a form a bit at a time. Industrial devices build up a form in layers. So you start with a design of an object, slice it into layers, and then build up the form a layer at a time. There are multiple technologies that can achieve this. See Michael's slides for the wide variety of 3D printer technology that is in use.
There are at least two main advantages to additive manufacturing over subtractive manufacturing: less waste and the ability to create forms that are impossible (or at least much more difficult) with subtractive manufacturing.
History of Additive Manufacturing
The first 3D printer that took digital design to reality was in 1984. These early machines would've been expensive. The first printer to break into the affordable hobbyist category was the RepRap. Steady progress has been made since then to the point that printers have become affordable and reliable enough that they are found in classrooms, offices, labs, and now in people's homes for their own personal use.
Current State of the Art
Most hobbyist printers are of the material extrusion (fused deposition modeling) variety. Or as Michael says, they extrude noodles, little plastic noodles. It is currently possible to get a decent 3D printer using this technology for around $500.
The typical material used for printing is either PLA or ABS. PLA has the advantage of being biodegradable and fumeless. ABS can be stronger, but generally gives off fumes and is not biodegradable.
Michael briefly gave an overview of the important hardware aspects of a noodle extruding 3D printer. They are:
- Stepper motors
- Controller board
- Print surface
- Rigid frame
How Michael Uses His Printer
Michael primarily uses his printer to create useful objects for his own use. He either starts with existing designs and modifies them, or he creates all new designs himself. Some examples of things he has printed:
- Mounting standoffs
- AA battery dispenser
- Pen holders
- Toothbrush holders
- Wrist brace
While Michael has been successfully printing lots of objects, he emphasized that 3D printing is more complicated than just how the printer works. While the technology has improved and continues to become more economical all the time, 3D printing isn't yet at the stage where you can just hop on down to the local store, pick up a printer in your price rage, take it home, and start printing things you find online or that you design yourself.
There are still many rough edges in the workflows and little standardization. For example, Michael often hand modifies the g-code produced by his tools (usually to adjust speed if I remember). Many of the tools also have all options that you may ever need exposed to the end user, which makes it difficult to learn and also makes it possible to select inappropriate combinations of options. Michael mentioned a tool that has an option labeled "fix horrible". He's not sure what it does, but he leaves it checked. However, watching Michael work, it is clear that 3D printing is definitely at the stage that diligence and attention to detail will pay off in the final products.
If you have a 3D printer, the typical workflow would be to design an object using a CAD tool. At this stage you will need to think ahead about how you intend the object to be printed. You even need to take into consideration aspects of the slicer tool. If you don't want to design something, then you can take an existing design from somewhere else and start with it.
After designing your object (or making a copy of an existing design), you import the object into a slicer program. This software is responsible for carving the object up into the layers we talked about before. It is also the tool that will allow you to decide how hollow your "solid" interiors will be. You can print your objects as mostly hollow with rigid support structures (see back lit photo below). You can also perform basic transformations in this tool. The slicer produces the g-code that is then fed to the printer.
After finishing up the main talk, Michael connected his laptop to his printer. He started the warm up process on the print bed.
While waiting for the print bed to warm up, he demonstrated the slicer software to us. His plan was to print a small coin which, according to the slicer, was going to only take seven minutes to print. He showed off the various transformations and adjustments that can be made inside the slicer (e.g. flipping axes or scaling up or down). He pointed out that even if you initially lack skill or confidence for designing objects, you can still achieve a lot by using existing designs and making adjustments in the slicer.
Speaking of print beds, Michael talked to Pat about the modifications he had made to his printer. Pat had added insulation which he said allowed the print bed to warm up about ten times faster. Once the print bed was ready, Michael started the print. In the short video below, you can see a close up of the printer in action and hear the sounds it makes as it travels. You can also hear Michael and John talk about the quantity of plastic on the spool.
As promised, the print job for the inch wide coin took about 7 minutes. Once it cooled, we had a nice new EAST Knowledge coin. The group got a kick out of passing around this newly manufactured piece. When you held it up to the light, you could see the support structures in the middle that allowed the coin to be hollow but still have rigidity.
The Time Passed too Quickly
Michael packed a lot of information into his presentation and still managed to answer questions and run a successful demo. It was a lot of fun for the audience. We'd all like to thank Michael for taking the time and effort to present to the group. And we'd like to thank Gresham’s Multnomah County Library for hosting us once again.
We hope to see you next time!
References and Resources
- Slides from Michael's talk
- Portland 3D Printing Lab - Portland 3D printing group on Meetup
- Thingiverse - design community focused primarily on 3D printable objects
- RepRap - "humanity's first general-purpose self-replicating manufacturing machine"
- PLA - Polylactic acid is the biodegrable plastic commonly used in 3D printign
- Formlabs Form 2 Teardown - Andrew (bunnie) Huang does a teardown of a 3D printer that uses vat photopolymerization
- G-code - Language used to drive computer numerical controlled evices